CVE-2005-2151: spf.c in Courier Mail Server does not properly handle DNS failures when looking up Sender Policy Framework (SP

Routine

MEDIUM 5.0DOWNGRADE

CVE-2005-2151 is a medium-severity flaw (CVSS 5.0) affecting courier mail server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

spf.c in Courier Mail Server does not properly handle DNS failures when looking up Sender Policy Framework (SPF) records, which could allow attackers to cause memory corruption.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Published	2005-07-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: double precision incorporated

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2005-07-06 04:00 UTCPublished CVE record published
2026-06-16 22:14 UTCUpdated Record last modified

double precision incorporated courier mail server DOWNGRADE

Affected: 0.46 · 0.47 · 0.48 · 0.48.1 · 0.48.2 · 0.49.0 · 0.50.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.46

1. Check installed version

apt-cache policy courier-mail-server || rpm -q courier-mail-server || courier-mail-server --version

2. No fixed release: DOWNGRADE to a release before 0.46 (Debian / Ubuntu)

apt-cache madison courier-mail-server sudo apt install courier-mail-server=<VERSION_BEFORE_0.46> sudo apt-mark hold courier-mail-server

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list courier-mail-server sudo dnf downgrade courier-mail-server-<VERSION_BEFORE_0.46> sudo dnf versionlock add courier-mail-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2005-2151?

courier mail server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2005-2151 being exploited?

CVE-2005-2151 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2005-2151 affect?

CVE-2005-2151 affects courier mail server. Severity is medium (CVSS 5.0). spf.c in Courier Mail Server does not properly handle DNS failures when looking up Sender Policy Framework (SPF) records, which could allow attackers to cause memory corruption.

How urgent is CVE-2005-2151?

Priority 33/100. No elevated risk signals yet.

Related CVEs

CVE-2021-38084 HIGH 8.1 UPGRADE An issue was discovered in the POP3 component of Courier Mail Server before 1.1.5
CVE-2005-3532 HIGH 7.5 DOWNGRADE authpam.c in courier-authdaemon for Courier Mail Server 0.37.3 through 0.52.1, when using pam_tally, does not

References

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